Soybean (Glycine max L. Merr) is a major cash crop and investment commodity in North America and elsewhere. Soybean oil is one of the most widely used edible oils, and soybeans are used worldwide both in animal feed and in human food production. Soybean root rot, caused by the fungal pathogen Phytophthora sojae (herein referred to as “phytophthora”), is the second most important disease in soybean production causing wide-spread yield loss in North & South America soy production regions. The symptoms of soybean root rot can affect soy plants at various stages of development from seed to maturity and the fungal oospore is able to survive in the soil for long durations of time allowing the disease to effect subsequent crops even in a crop rotation cycle. Symptoms include seed rot, yellowing or browning of the leaves, root death and eventual plant death.
Different varieties of soybean vary in their sensitivity or tolerance to phytophthora. Therefore, one of the most effective control measures is planting phytophthora tolerant soybean varieties, and thus varietal selection is important for the management of phytophthora. However, currently, determining whether a soybean cultivar might have tolerance to phytophthora typically involves testing each cultivar in the field or greenhouse under conditions that typically produce soybean root rot. Thus, the present invention overcomes the shortcomings in the art by providing markers associated with tolerance to phytophthora, thereby allowing the characterization of soybean cultivars for phytophthora by molecular analysis rather than phenotypic analysis.